Kinetics of Soil Chemical Processes: Past Progress and Future Needs

2015 ◽  
pp. 61-73
Author(s):  
Donald L. Sparks
Keyword(s):  
Chemical Processes ◽  
Future Needs ◽  
Kinetics Of

Elastic Properties of Steps at Interphase Boundaries

1991 ◽  
Vol 238 ◽  
Author(s):  
G. J. Shiflet
Keyword(s):  
Energy Density ◽  
Elastic Properties ◽  
Mathematical Analysis ◽  
Strain Energy ◽  
Chemical Processes ◽  
Diffusion Kinetics ◽  
Interphase Boundaries ◽  
Kinetics Of ◽  
Maximum Stresses

ABSTRACTStresses are introduced in crystals at interphase boundaries where steps improve the registry of atoms. A model and mathematical analysis based on an approach previously taken by van der Merwe and Shiflet1–4 of the problem incorporating a coherent step are presented. Computed distributions of stresses, strains, dilatation and energy density in the form of contours and nets are given for a coherent monatomic step. It is concluded that the maximum stresses are quite large and the fields decay fairly rapidly with distance from the steps, the gradient of dilatation around steps will significantly affect diffusion kinetics of impurities and the strain energy seems too low to significantly enhance chemical processes.

scholarly journals Study of Hydrogen Generation of Aluminum-Containing Compositions with Boric Acid

2018 ◽  
Vol 3 (3) ◽  
pp. 230
Author(s):  
Salakhova A.A. ◽  
Suvorov V.A. ◽  
Firsova A. I. ◽  
Belozerov V.I. ◽  
Milinchuk V.K.
Keyword(s):  
Boric Acid ◽  
Hydrogen Generation ◽  
Sodium Metasilicate ◽  
Chemical Processes ◽  
System Management ◽  
Control Rod ◽  
Radiation Fields ◽  
Fuel Elements ◽  
And Control ◽  
Kinetics Of

The results of investigations of the kinetics of hydrogen generation compositions with aluminum, chemical activators (hydrated sodium metasilicate, oxide and calcium hydroxide) boric acid. Aluminium and its alloys used for the manufacture of protective sheaths of fuel elements and control rod protection system management, pipelines, tanks, and various support structures in the active zone of atomic reactors RBMK, research water-cooled reactors. The aluminum is protected from direct contact with water and steam surface layer of metal oxide having a high corrosion resistance at high temperatures in powerful radiation fields. However, after removal or when the discontinuity of the oxide layer of activated metal efficiently decompose water to hydrogen. It is established that the hydrogen aluminum-containing compositions is dependent on the concentration of boric acid. The discovery of the involvement of boric acid in these reactions expands the ideas about regularities of chemical processes of formation of hydrogen flowing in the water coolant of VVER reactors with the participation of the corrective additives and impurities.

Feasibility Study of Raman Spectroscopy as a Tool to Investigate the Liquid-Phase Chemistry of Aliphatic Organic Peroxides

1997 ◽  
Vol 51 (1) ◽  
pp. 74-80 ◽  
Author(s):  
Peter Jacob ◽  
Bernhard Wehling ◽  
Wieland Hill ◽  
Dieter Klockow
Keyword(s):  
Hydrogen Peroxide ◽  
Raman Spectroscopy ◽  
Liquid Phase ◽  
Chemical Processes ◽  
Organic Peroxides ◽  
Time Resolved ◽  
In Situ Investigation ◽  
Phase Chemistry ◽  
Kinetics Of

The described investigations are focused on peroxides occurring as products in atmospheric chemical processes, namely, hydrogen peroxide, methylhydroperoxide, hydroxymethylhydroperoxide, bis-(hydroxymethyl)peroxide, 1-hydroxyethylhydroperoxide, bis-(hydroxyethyl)peroxide, and hydroxymethylmethylperoxide. The compounds are identified and determined through the position and intensity of their characteristic O–O stretching bands in the range between 767 and 878 cm−1. Time-resolved Raman spectroscopy of peroxide solutions permits the in situ investigation of pathways and kinetics of reactions between peroxides and aldehydes.

Bases of the Kinetics of Chemical Processes

1996 ◽  
Vol 35 (6) ◽  
pp. 841-856
Author(s):  
E. F. Vainshtein ◽  
G. E. Zaikov
Keyword(s):  
Chemical Processes ◽  
Kinetics Of

A two-stage model for the formation of clay minerals from tephra-derived volcanic glass

Clay Minerals ◽  
1990 ◽  
Vol 25 (3) ◽  
pp. 313-327 ◽  
Author(s):  
A. P. W. Hodder ◽  
B. E. Green ◽  
D. J. Lowe
Keyword(s):  
Clay Minerals ◽  
Late Quaternary ◽  
Volcanic Glass ◽  
Chemical Processes ◽  
Diffusion Controlled ◽  
Tephra Layers ◽  
Clay Formation ◽  
Kinetics Of ◽  
Calculated Activation ◽  
Rhyolitic Tephra

AbstractThe kinetics of clay formation in buried paleosols developed from late Quaternary rhyolitic tephra layers near Rotorua, New Zealand, can be described in terms of a combination of parabolic and linear kinetics, reflecting the hydration of glass, and the formation of clay minerals, respectively. Such a model is consistent with the formation of clay minerals showing an Arrhenian temperature dependence and suggests, on the basis of calculated activation energies, that the process of formation of Al-rich allophane (imogolite) is diffusion controlled, whereas the rate of formation of Si-rich allophane is controlled by the chemical processes at the site of reaction.

Kinetics of physico-chemical processes during intensive mechanical processing of ZnO–MnO2 powder mixture

2011 ◽  
Vol 323 (20) ◽  
pp. 2429-2435 ◽  
Author(s):  
M. Kakazey ◽  
M. Vlasova ◽  
M. Dominguez-Patiño ◽  
E.A. Juarez-Arellano ◽  
A. Bykov ◽  
...  
Keyword(s):  
Powder Mixture ◽  
Chemical Processes ◽  
Mechanical Processing ◽  
Physico Chemical ◽  
Kinetics Of

Modeling of Physical and Chemical Processes of Anodic Bonding Technology

2014 ◽  
Vol 1040 ◽  
pp. 513-518 ◽  
Author(s):  
N.S. Pshchelko ◽  
M.P. Sevryugina
Keyword(s):  
Electric Fields ◽  
Chemical Processes ◽  
Anodic Bonding ◽  
Charge Accumulation ◽  
Charge Layer ◽  
Bonding Technology ◽  
Time Required ◽  
A Charge ◽  
Physical And Chemical ◽  
Kinetics Of

Modeling ideas of physical and chemical processes when using an anodic bonding for materials connection are developed. The kinetics of a charge accumulation in an electrode region in a dielectric is considered. The thickness of a charge layer, electric fields strength and value of the ponderomotive pressure providing connection of materials are calculated. It is shown that the necessary ponderomotive pressure resulting in a dielectric-to-conductor seal is normally about ten MPa and the time required is about ten minutes.

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